Intracellular recording experiments in the mudpuppy (Necturus maculosus) have demonstrated that depolarizing bipolar show a one-half to one log unit higher threshold to light stimuli and a longer latency when compared to hyperpolarizing bipolars. This threshold difference cannot be ascribed to differences in rod and cone connections. Experimentally it was possible to use these differences to evaluate postbipolar cell connections; such experiments support the idea that some neurons are connected to one or the other bipolar cell type, while on-off cells receive input from both.
Bibliographical noteFunding Information:
This research was sponsored by the National Institutes of Health Grant EY01802 awarded to T. E. Frumkes and EY00844 awarded to R. F. Miller. We appreciate the helpful assistance of R. F. Dacheux.